Our company is running IIS5 SP2 installed.Since hours all Web-Services are stopped and started permanently every few minutes:"IIS stop command received from user NT AUTHORITY\SYSTEM. The logged data is the status code""Service terminated unexpectedly" error with an event ID of 7031

OK I know this is very few information but maybe someone can help......

Make sure the IIS machine wasnt comprimised with the last few worms running around the internet. As of this morning over 12000 servers are supposed to be infected. That could be what s happening with your server. Otherwise, you might have to call up M$, because IIS is over my head